Heat exchanger with expansible tube seal



March 28, 1967 J. H. cox ET AL HEAT EXGHANGER WITH EXPANSIBLE TUBE SEAL 2 Sheets-Sheet 1 Filed Jan. 2, 1964 IN V EN TOR 3 JOSEPH H. COX. WILLIAM C. MARTIN, JR.

WJWW

ATTORNEY.

, March 28, 1967 J. H. cox ET AL 3,311,164

HEAT EXCHANGER WITH EXPANSIBLE TUBE SEAL 7 Filed Jan. 2, 1964 2 Sheets-Sheet 2 FIG. 4 2 I04 I28 I04 FIG. 3 FIG. 5

INVENTORS JOSEPH H. COX. WILLIAM C MARTIN, JR.

ATTORNEY.

United States Patent C) 3,311,164 HEAT EXCHANGER WITH EXPANSIBLE TUBE SEAL Joseph H. Cox, Solvay, and William C. Martin, Jr., Syracuse, N.Y., assignors to Carrier Corporation, Syracuse, N .Y., a corporation of Delaware 7 Filed Jan. 2, 1964, Ser. No. 335,248 12 Claims. (Cl. 165-95) This invention relates to heat exchange apparatus, and more particularly to a heat exchanger for use in refrigeration systems.

Heat exchangers may be thought of as devices for bringing primary heat exchange medium into heat exchange relationship with secondary heat exchange medium. A typical heat exchanger includes a plurality of longitudinally disposed heat exchanger tubes in a housing. In a heat exchanger of this type the area surrounding the exterior surfaces of the plural heat exchanger tubes may be in communication with the primary heatexchange medium while the area bounded by the interior surfaces of the heat exchanger tubes communicates with the secondary heat exchange medium. By this construction the plural heat exchanger tubes serve as the intermediary for bringing primary heat exchange medium into heat exchange relationship With the secondary heat exchange medium.

The efficacy of the heat exchanger requires that the primary and secondary heat exchange mediums be isolated one from the other. Since the plural heat exchanger tubes constitute the sole bridge between primary and secondary heat exchange mediums the seal between primary and secondary heat exchange mediums at each of the plural heat exchanger tubes is of critical importance.

In a known method of effecting a fluid-tight seal between primary and secondary heat exchange mediums, the opposite ends of each heat exchanger tube are expanded into contact with a partitioning structure, known as a tube sheet, in the heat exchanger housing separating the primary and secondary heat exchange mediums. This assembly procedure is time-consuming and expensive, particularly in heat exchangers having a substantial number of heat exchanger tubes.

Where heat exchangers of the type described are disposed in positions other than vertical, the plural heat exchanger tubes tend to sag. Tube sag may place an excessive strain on the seal between the partitioning structure and the plural heat exchanger tubes with possible impairment or rupture thereof. Additionally, the amount of sag of each of the plural heat exchanger tubes may vary, destroying the design spacing between each of the tubes and bringing tubes into contact with one another. The flow of first and second heat exchange mediums through the heat exchanger may induce the heat exchanger tubes to vibrate causing contacting or closely adjacent tubes to strike one another. 1

To obviate sag in heat exchanger tubes, additional supports, commonly known as tube support sheets, may be placed at selected intervals in the heat exchanger housing. The heat exchanger tubes pass through spaced openings in the tube support sheet, the encompassing tube support sheet structure preventing movement of the tube in a radial direction.

In constructions where tube support sheets are utilized, it may be appreciated that the most effective support structure for maintaining the heat exchanger tubes in predetermined spaced relation relative to the housing and to each other is a support sheet having tube receiving openings dimensioned approximately equal to or slightly less than the outer dimension of the heat exchanger tubes. In

' this arrangement each heat exchanger tube is rigidly poa port sheet surface at the tube receiving opening.

ever, as noted heretofore, the known technique of exmit relative movement between heat exchanger tubes and tube support sheets during heat exchanger assembly, tube support is compromised by making the tube support sheet openings larger than the outer dimension of the heat exchanger tubes. This compromise arrangement provides a degree of support for each heat exchanger tube, and at the same time permits movement of the heat exchanger tubes through the support sheets during assembly, and disassembly, of the heat exchanger. It does not, however, support the heat exchanger tubes tightly enough to eliminate sag of tubes between supports, and tube vibration.

To more effectively support the heat exchanger tubes, each heat exchanger tube may be expanded into contact with each of the tube support sheets subsequent to the insertion of the heat exchanger tube therethrough. This construction permits the use of tube support sheet openings with a dimension greater than the outer dimension of the heat exchanger tubes whereby assembly of the heat exchanger is facilitated and at the same time results in a high degree of tube support through the subsequent expansion of each tube into tight engagement with the tube support sheet. However, this construction is expensive, time-consuming and often impractical. Where heat exchangers have a substantial axial length with a great number of relatively small diameter heat exchanger tubes and plural spaced tube support sheets, the magnitude of the problem facing the assembler in accurately locating and expanding that portion only of each heat exchanger tube opposite each tube support sheet through which the tube passes may be readily appreciated.

Conventional tube sheets and tube support sheets are normally formed from metal, usually steel. Contact of the steel tube sheet with the outer surface of the heat exchanger tubes and the tube support sheet with the outer surface of the heat exchanger tubes may result in galvanic erosion where copper heat exchanger tubes are employed. This may be enhanced by the particular heat exchange medium utilized in the system and by any tube vibration. Where the tube sheet and/or tube support sheet is formed from the same metallic material as the heat exchanger tubes, erosion induced by vibration of the heat exchanger tubes may occur. To obviate tube erosion at the tube sheets and tube support sheets, each heat exchanger tube should preferably tightly engage the sup- Howobject of the present invention to provide a new and im-' proved apparatus for maintaining heat exchanger tubes in predetermined spaced relationship relative to one an other and to the heat exchanger.

It is an additional object of the present invention to provide a novel heat exchanger construction incorporating a sealing mechanism at the heat exchanger tubes initially operable to effect a deformable seal whereby assembly of the heat exchanger is facilitated and operable on heat exchanger use to establish a fluid-tight seal.

It is a further object of this invention to provide a unique tube supporting apparatus for use in heat exchangers adapted to permit ready movement of the heat exchanger tubes therethrough during assembly of the heat exchanger and operable during heat exchanger use to prevent movement of the heat exchanger tubes relative to one another and to the heat exchanger.

It is an object of the present invention to provide apparatus for fixedly positioning heat exchanger tubes within the heat exchanger during operation thereof.

1 It is a further object of the present invention to provide a new and improved tube sheet and tube support sheet structure.

This invention relates to a heat exchanger adapted to communicate with a first heat exchange medium having at least one heat exchange member therein adapted to communicate with a sec-nd heat exchange medium, the

combination comprising means for supporting the heat exchange member in the heat exchanger, the support means being spaced from the heat exchange member, and expansible means for securing the heat exchange member to the support means including means for resiliently holding the heat exchange member before expansion of the expansible member.

This invention further relates to heat exchange apparatus comprising means including opposite walls defining a compartment in communication with heat exchange medium in a predetermined first condition, at least one heat exchanger tube in the compartment in communication with the heat exchange medium in a predetermined second condition, each wall being provided with an opening therethrough having a dimension larger than the outer dimension of the heat exchanger tube to accommodate the heat exchanger tube therethrough, and sealing means in the space between the tube and the portion of each wall defining the tube receiving opening operable to inhibit flow of heat exchange medium between the tube and the wall openings, the sealing means being comprised of a material adapted when exposed to the heat exchange medium to expand to establish a fluid-tight seal between the outer periphery of the heat exchanger tube and the portion of the wall defining the opening.

Other objects will be apparent from the ensuing description and drawings in which:

FIGURE 1 illustrates schematically a refrigeration system incorporating the present invention;

FIGURE 2 is across sectional view taken along lines IIII of FIGURE 1 showing the tube support sheet;

I FIGURE 3 is an enlarged fragmentary cross sectional view through the tube support sheet of FIGURE 2 showing the expansible tube gripping elements in unexpanded condition;

FIGURE 4 is a cross sectional view of a heat exchanger constructed according to an alternate embodiment of the invention; and Y FIGURE 5 is an enlarged fragmentary cross sectional View through the tube sheet of the heat exchanger shown in FIGURE 4 of the drawings showing the expansible tube gripping elements in unexpanded condition.

Referring particularly to FIGURE 1 of the drawings, there is shown a refrigeration system embodying the heat exchanger tube support structure of the present invention. The refrigeration system includes a compressor 12 having a suitable drive motor 14. Compressor 12 may be of any suitable type, for example, centrifugal, rotary or reciprocating; if desired, compressor 12 may be housed with motor 14 to form a hermetic unit. It is understood that the present invention may be embodied in absorption type refrigeration systems.

Compressor 12 compresses vaporous primary heat exchange medium or refrigerant flowing through line 3 from the heat exchanger 2, acting as an evaporator, The compressed gaseous refrigerant is discharged through line 11 into heat exchanger 20, acting as a condenser. Gaseous refrigerant entering heat exchanger 20 is liquefied through heat transfer with a secondary heat exchange medium, for example, water circulating through the heat exchanger tubes 22. Liquid refrigerant from heat exchanger 20 passes through line 24 and suitable expansion means 26,

for example, a thermal expansion valve, through line 36 to the heat exchanger 2. Expansion means 26 provides the requisite pressure drop between the heat exchangers during system operation. Liquid refrigerant in heat exchanger 2 is vaporized through heat transfer with the media to be cooled or chilled, for example, water circulating in the heat exchanger coils thereof.

Heat exchanger 2t comprises a generally cylindrical shell or housing 40 with opposite end members or tube sheets 42, 43 sealingly attached thereto to define cylin- V drical compartment 41. Tube sheets 42, 43 support plural heat exchanger coils or tube 22 passing through compartment 41. A pair of headers 45, 46 are sealingly attached to tube sheets 42, 43 respectively and define therewith end compartments 47, 48. Compartment 47 is separated by member 50' into inlet and discharge chambers 52, 54 respectively in communication with suitable secondary heat exchange medium.

Tube sheets 42, 43 are each provided with an equal number of spaced openings 69, 61 therethrough, each of the openings 60 in tube sheet 42 being in axial alignment with a corresponding opening 61 in the opposite tube sheet 43. The terminal ends of each heat exchanger tube 22 pass through a pair of axially aligned openings 60, 61. Each terminal end of the heat exchanger tubes 22 may be expanded by suitable means (not shown) into tight engagement with the inner surface of the tube sheet 42 or 43 defining the openings 60, 61 respectively to tightly seal compartment 41 from the opposite end compartments 47, 48. Heat exchanger tubes 22 may be grouped at 21, 23 into what are commonly known as tube bundles. Tube bundles 21, 23 communicate inlet and discharge chambers 52, 54 respectively of compartment 47 with the opposite end compartment 48. Refrigerant lines 11 and 24 communicate the heat exchanger compartment 41 with the system compressor 12 and expansion means 26 respectively.

During operation of the frigeration system, cooling medium from conduit 56 flows through inlet chamber 52 and heat exchange-r tube bundle 21 into compartment 48, and from compartment 48 through heat exchanger tube bundle 23 and outlet chamber 54 into discharge conduit 57. Gaseous refrigerant from the compressor 12 passes through line 11 into compartment 41 of the heat exchanger Ztl. Liquid refrigerant in compartment 41 flows through line 24 and expansion means 26 to heat exchanger 2.

Referring to FIGURES l and 2 of the drawings, one or more tube support sheets or bafiles 70 are shown. Sheets 70 may be formed with paired diametrically opposite arcuate peripheral sides 71 and planar peripheral sides 72 respectively. Arcuate sides 71, having a radius substantially equal to the radius of cylindrical heat exchanger shell 40, abut the inner surface of shell 40.

In constructions where it is intended that tube support sheets 70 additionally function as baffies to route the flow of refrigerant through heat exchanger compartment 41, tube support sheet 70 may be formed with an arcuate peripheral side terminating in a single planar peripheral side. The arcuate side, at a radius substantially equal to the radius of cylindrical heat exchanger shell 40, abuts the inner surface of the shell 40.

A plurality of openings 74 having an inner dimension slightly greater than the outer dimension of the heat exchanger tubes 22 is provided in each tube support sheet 70. Each of the openings 74 is disposed in axial alignment with a corresponding pair of openings 60, 61 in tube sheets 42, 43 respectively. Tube support sheet or sheets 70 are located within cylindrical heat exchanger compartment 41 in predetermined spaced relationship to tube sheets 42, 43. Preferably, tube support sheet or sheets 70 are fixedly secured to the inner surface of shell 40 by suitable means (not shown). The coaxial relationship between each of the plural tube receiving openings in the support sheets 70 and a pair of tube receiving openings in support sheets 42, 43 establishes a substantially straightline path for each heat exchanger tube.

Use of supporting structure of the type described heretofore having openings therein for receiving heat exchanger tubes presents two diametrically opposite problems. In order to assemble the heat exchanger and to permit removal of one or more heat exchanger tubes for repair or replacement, the tube openings in the sup port sheet or sheets must have a dimension greater than the outer dimension of the heat exchanger tubes. By this means relative movement between the tubes and the support sheets, necessary during assembly of the heat exchanger, may be effected. Efiicient tube support, however, decrees that the support sheet closely surround, and preferably tightly grip, the heat exchanger tube. It is appreciated therefore that if the dimension of the support sheet opening too closely approximates the outer dimension of the heat exchanger tube, tube support may be realized at the expense of very diflicult, or impossible, movement of the heat exchanger tubes through the support sheet openings. If the dimension of the support sheet openings be sufficiently great thereby permitting ready insertion, and withdrawal, of the heat exchanger tubes, excessive tube vibration and sag between adjacent supports may occur. I

Applicants novel arrangement, hereinafter described, permits the use of tube support sheets with tube receiving openings therein large enough to permit ready movement of the heat exchanger tubes therethrough during assembly or disassembly of the heat exchanger while providing tight engagement between the support sheet and the heat exchanger tube passing therethrough.

In FIGURE 3 of the drawings, an enlarged view of applicants novel heat exchanger tube support structure is therein shown. Tube support sheet or bathe 70 having a plurality of tube receiving openings 74 therein is preferably formed from a thermosetting resin. Other suitable rigid materials, for example, metal, may be contemplated. Where support sheet 70 is formed from a thermosetting resin, reinforcing means (not shown) of any suitable organic or inorganic material may be formed integrally therewith to enhance the rigidity thereof. Suitable reinforcing material may comprise metallic wire or thread, glass fiber thread or chopped and randomly oriented glass fiber particles. Tube receiving openings 74 have a diameter slightly greater than the outer diameter of the heat exchanger-tubes 22 to facilitate movement of the tubes therethrough during assembly and disassembly of the heat exchanger. Preferably, tube support sheets 70 are bevelled at 82 to minimize chipping of the tube support sheet during movement of tubes 22 through openings 74.

A portion of each of the openings 74 in tube support sheet 70 is defined by the inner surface 83 of ring-like member 86 imbedded in tube support sheet 70 coaxial with tube receiving opening 74. As will be more particularly explained hereinafter, ring-like member 86 is formed from a resilient incompressible material adapted to swell or expand on exposure to the system refrigerant. By closely surrounding the sides and outer periphery of expansible member 86 with relatively rigid tube support sheet structure 70, swell or expansion of member 86 on exposure to the system refrigerant is confined to a radially inward direction. Since the expansible member 86 tends to expand uniformly when in the presence of refrigerant atmosphere, the closely surrounding tube support structure channels the entire expansion of member 86 radially inward to bring inner surface 83 into tight engagement with the outer periphery of the heat exchanger tube in opening 74-. Inner surface 83 of member 86 includes a gripping portion 90 having a dimension, before expansion of member 86, substantially equal to the dimension of tube receiving opening 74 and a radially inward extending lip portion 92 defining an opening having a dimension less than the outer dimension of the heat exchanger tubes 22.

6 Expansible members 86 are comprised of an elastomeric material adapted to expand or swell on exposure to a particular refrigerant. A composition adapted to expand in the presence of monoflurotrichloromethane (CCl F), commonly known as refrigerant R-ll, is shown in the following example (in parts by Weight):

2-chloro-1,3-butadiene 100 Stearic acid 0.5 10 Magnesium oxide 2 Carbon black 80. Zinc oxide 5 Z-mercaptoimidazoline Q 0.5

An example of a composition adapted to swell when exposed to a lithium bromide (LiBr) solution, useful in absorption refrigeration systems, is as follows (in parts by weight):

In assembly of heat exchanger 20, tube support sheets or baflles 70 may be fixedly positioned in compartment 41 by suitable means (not shown) with tube openings 74 therein in axial alignment with respective pairs of tube sheet openings 60, 61. Each of the heat exchanger tubes 22 is passed through a tube sheet opening 60 or 61 through each of the tube support sheet openings 74 axially aligned therewith into the opposite tube sheet 60 or 61. Disposition of tubes 22 having an outer dimension greater than the dimension of the opening defined by lip portion 92 of members 86 in openings 74 of tube support sheets 70 distends lip portions 92 of members 86 outwardly whereby The end portions of each of the heat exchanger tubes 22 may be thereafter expanded by suitable means (not shown) into tight engagement with that part of tube sheets 42, 43 defining openings 60, 61 respectively. On exposure to the system refrigerant, for example, when the system is charged with refrigerant, members 86 expand or swell. As noted heretofore, the closely surrounding tube support sheet structure channels expansion of members 86 radially inward to bring gripping portion 90 thereof into tight engagement with that portion of the outer periphery of the heat exchanger tube 22 opposite thereto to securely connect the heat exchanger tubes with the tube support sheets.

Subsequent purging of refrigerant from the system causes members 86 to contract disengaging gripping portion 90 from the heat exchanger tubes whereby movement of the tubes relative to the tube support sheets may be effected. Disengagement of heat exchanger tube end portions from tube sheets 42, 43 permits withdrawal of the tube from the heat exchanger.

While applicants novel tube support structure is described in connected with the system heat exchanger 20, it is understood that heat exchanger 2 may be similarly constructed.

lip portions 92 resiliently grip heat exchanger tubes 22.

As noted heretofore, tube receiving openings 60, 61 in sealed joint between the heat exchanger tubes 22 and and and tube support sheets 42, 43 and to fixedly support the heat exchanger tubes 22 in heat exchanger 20.

Referring to FIGURES 4 and 5 of the drawings, applicants therein provide a novel heat exchanger having a new and improved tube sheet construction wherein the required expansion of the terminal ends of each heat exchanger tube into tight engagement with the tube sheet is obviated. Referring particularly to FIGURE 4 of the drawings, a heat exchanger 100 is therein shown comprising a generally cylindrical shell or housing 102 having opposite end members or tube sheets 104 sealingly attached thereto to define cylindrical compartment 106. Tube sheets 104 are provided with plural pairs of axially aligned openings 107 therein for receiving the terminal ends of plural heat exchanger tubes 108 in a manner to be more particularly explained hereinafter. Tube sheet openings 107 have a dimension slightly greater than the outer dimension of heat exchanger tubes 108 to permit movement of the heat exchanger tubes therethrough during assembly of the heat exchanger 100. A pair of headers 110, 112 sealingly secured to tube sheets 104 define end compartments 114, 116 respectively. End compartment 116 is separated by a partition 118 into inlet and discharge chambers 120, 122 respectively. Inlet and discharge conduits 124, 126 respectively communicate chambers 120, 122 respectively with a suitable source of secondary heat exchange medium. Inlet and discharge conduits 128, 130 respectively communicate heat exchanger compartment 106 with a suitable source of primary heat exchange medium.

Referring particularly to FIGURE 5 of the drawings, the portion of tube sheets 104 defining tube receiving openings 107 includes part 132 comprised of a suitable resilient material adapted to expand uniformly when exposed to system heat exchange medium. Part 132 comprises the inner surface of a ring-like member 134 imbedded in tube sheet 104 coaxial with tube receiving opening 107. The inner part 132 of expansible members 134 is formed with a gripping portion 136 having a dimension before exposure of member 134 to heat exchange medium substantially equal to the dimension of tube receiving openings 107 in tube sheets 104 and a radially inward extending lip portion 138 defining an opening having a dimension less than the outer dimension of heat exchanger tubes 108. Ring-like members 134 are formed from a suitable resilient, incompressible material adapted to swell or expand when exposed to heat exchange medium. Suitable exemplary compositions for ring-like members 134 are described heretofore.

Tube sheets 104 are formed from a suitable relatively rigid material. In a preferred embodiment, tube sheets 104 are formed, as by molding, from thermosetting resin material. Where tube sheets 104 are formed by molding, expansible members 134 are preferably molded integrally therewith. Tube sheets 104 may be formed from other suitable relatively rigid materials such as metal. Where tube sheets 104 are formed from a suitable thermosetting resin, reinforcing means (not shown) of any suitable organic or inorganic material, such as metallic wire or thread, may be formed integrally therewith to enhance tube sheet rigidity. Tube sheets 104 are preferably bev elled at 140 to minimize chipping of the tube sheet surfaces circumjacent tube receiving openings 107 during movement of the heat exchanger tubes 108 therethrough.

In assembly of the heat exchanger 100, heat exchanger tubes 108 are passed through each of the openings 107 in one of the tube sheets 104, through compartment 106 into the tube receiving opening in axial alignment therewith in the opposite tube sheet 104. When assembled, each of the heat exchanger tubes 108 is supported by its terminal ends positioned in openings 107 in tube sheets 104. If desired, tube support sheets may be provided between the oppositely disposed tube sheets 104 to further support heat exchanger tubes 108 in heat exchanger compartment 106.

Insertion of heat exchanger tubes 108 having an outer dimension greater than the dimension of the opening defined by lip pontion 138 of expansible members 134 in openings 107 in tube sheets 104 distends lip portion 138 outwardly causing lip portion 138 to resiliently grip the periphery of heat exchanger tube 108 opposite tube sheet opening 107. The resilient gripping 'action of lip portions 138 of expansible members 134 before exposure, and consequent expansion, of members 134 to heat exchange medium serves to retain the heat exchanger tubes in assembled position, and additionally establishes a seal effective to prevent or impede the flow of heat exchange medium through the space between heat exchanger tubes 108 and tube sheets 104.

To enhance the effectiveness of lip portion 138 as a seal, lip portions 138, during assembly of the heat exchanger, are distended in the direction of the high pressure side of heat exchanger by a suitable means (not shown). In the embodiment shown in FIGURES 4 and 5 of the drawings, lip portions 138 of members 134 extend in the direction of compartment 106 which is adapted to communicate with a relatively high pressure primary heat exchange medium.

On exposure to system heat exchange medium, the ringlike members 134 expand. The closely surrounding tube sheet structure channels expansion of the members 134 radially inward to bring gripping portion 136 thereof into tight engagement with the outer periphery of heat exchanger tubes 108 to securely fix heat exchanger tubes 108 in tube sheets 104 and establish a fluid-tight seal between the outer periphery of the heat exchanger tubes and tube sheets 104 to prevent flow of heat exchange medium between compartments 106 and 114, 116.

Since the efficacy of the seal between compartment 106 of heat exchanger 100 and end compartments 114, 116, in communication with primary and secondary heat exchange mediums respectively, is initially dependent upon the resilient force with which lip portion 138 of expansible members 134 grips heat exchanger tubes 108, applicants envision utilization of heat exchangers constructed according to the embodiment of FIGURES 4 and S in systems having compatible primary and secondary heat exchange mediums. For example, a system employing relatively high temperature water as a primary heat exchange medium and relatively low temperature water as a secondary heat exchange medium may be contemplated.

It is understood that the terminal ends of heat exchanger tubes 108 may be expanded by a suitable means (not shown) into tight engagement with tube sheets 104. By this construction should heat exchange medium in the system pass between the expanded outside surface of heat exchanger tubes 108 and tube sheets 104, the expansible members 134, upon contact with the heat exchange medium, swell or expand. Expansion of members 134 brings the inner surface part 132 thereof into tight engagement with the outer surface of heat exchanger tubes 104 opposite opening 107 to interrupt flow of refrigerant between compartments 106 and 114, 116 of heat exchanger 100.

While we have shown preferred embodiments of the present invention, it will be obvious that other modifications may be made without departing from the scope of the invention as limited only by the appended claims.

We claim:

1. In a heat exchanger adapted to communicate with a first heat exchange medium having at least one heat exchange member therein adapted to communicate with a second heat exchange medium, the combination comprising means for supporting said heat exchange member in said heat exchanger, said support means being spaced from said heat exchange member, and expansible means for securing said heat exchange member to said support means, said expansible means being comprised of an elastomeric material swellable through contact with said first medium and including a part normally engageable with said heat exchange member to resiliently grasp said heat exchange member before swelling of said expansible means, said elastomeric material being substantially unaffected by temperature conditions of said medium.

2. A heat exchanger according to claim 1 in which said expansible means is positioned between said heat exchange member and said support means.

3. A heat exchanger according to claim 1 in which said expansible means part defines an opening for receiving said heat exchange member, the dimension of said opening being slightly less than the outside dimension of said heat exchange member so that said expansible means part snugly encompasses said heat exchange member before swelling of said expansible means.

4. Heat exchange apparatus including a compartment in communication with a first heat exchange medium with at least one heat exchanger tube in said compartment in communication with a second heat exchange medium, the combination comprising means in said compartment having an opening therein for supporting said heat exchanger tube, said heat exchanger tube extending through said opening, and expansible'means in said opening adjacent said heat exchanger tube, said expansible means being comprised of an elastomeric material swellable through contact with said firs heat exchange medium to tightly grip said heat exchanger tube to secure said tube -in place in said support means, said expansible means including a radially inwardly projecting lip-like part adapted to engage the outer wall of said heat exchanger tube to releasably hold said heat exchanger tube before swelling of said expansible means.

5. Heat exchange apparatus according to claim 4 in which said expansible means comprises a ring-like member coaxial with said support means opening and having a dimension before expansion substantially equal to the dimension of said support means opening, said expansible means lip-like part having a dimension less than the outer dimension of said heat exchanger tube.

6. Heat exchange apparatus according to claim 5 in which said ring-like member is imbedded in said support means.

7. In a heat exchanger the combination of means defining a compartment adapted to communicate with heat exchange medium including opposite side walls having at least one tube receiving opening therethrough, each of said tube receiving openings in one side wall being in axial alignment with one of the tube receiving openings in the other side wall, a heat exchanger tube in said compartment extending through each pair of axially aligned tube receiving openings, said tube receiving openings having a dimension greater than the outer dimension of said heat exchanger tube, a part of the wall surface of each tube receiving opening being comprised of an annular elastomeric seal swellable through contact with said heat exchange medium, said annular elastomeric seal being substantially unaffected !by temperature conditions of said heat exchange medium a portion of said seal normally engaging the periphery of said heat exchanger tube so as to restrict flow of heat exchange medium between said heat exchanger tube and said wall surface before expansion of said seal, said seal being adapted upon swelling to sealingly grip the outer wall of said heat exchanger tube.

8. Heat exchange apparatus according to claim 7 in which said seal comprises a ring-like element imbedded in each of said walls adjacent each of said tube receiving openings, said element having a lip portion defining an opening with a dimension less than the outer dimension of said heat exchanger tube and a gripping portion having a dimension before expansion of said element substantially equal to the dimension of said wall opening.

9. Heat exchange apparatus according to claim 7 in which said walls are comprised of a thermo-setting resin.

10. In a heat exchanger the combination of an enclosure, partition means in said enclosure, said enclosure defining first, second, and third compartments, means communicating said first compartment with heat exchange medium in a predetermined first condition, means com municating said second compartment with said heat exchange medium in a predetermined second condition, plural heat exchanger tubes communicating said first compartment with said third compartment, said tubes passing through said second compartment to bring heat exchange medium in said first predetermined condition into heat exchange relationship with heat exchange medium in said second predetermined condition, and elastomeric sealing means between each of said heat exchanger tubes and said partition means initially operable to impede the flow of heat exchange medium between the outer periphery of said heat exchanger tubes and said partition means, said elastomeric sealing means comprising a material operable through contact with said medium to expand to establish a fluid-tight seal between said first and second, said material being substantially unaffected by temperature conditions of said medium and said second and third compartments. 1

11. A heat exchanger according to claim 10 in which said sealing means includes a gripping portion having a dimension before expansion thereof greater than the outer dimension of said heat exchanger tubes, said gripping portion being operable on exposure of said sealing means to said heat exchange medium to move radially inward into tight engagement with the outer peripheral surface of said heat exchanger tubes.

12. A heat exchanger as recited in claim 10 in which said sealing means comprises a ring-like element imbedded in said partition having a first portion defining an opening with a dimension less than the outer dimension of said heat exchanger tubes operable to resiliently hold said heat exchanger tubes to prevent flow of heat exchange medium between said heat exchanger tubes and said partition means, and a second portion with a dimension before expansion of said element greater than the outer dimension of said heat exchanger tubes whereby expansion of said element on exposure to said heat exchange medium brings said second portion into tight engagement with the outer peripheral portion of said heat exchanger tubes.

References Cited by the Examiner UNITED STATES PATENTS MEYER PERLIN, Primary Examiner.

FREDERICK L. MATTESON,

OLEARY, Examiners.

A. W. DAVIS, Assistant Examiner.

JR., ROBERT A. 

10. IN A HEAT EXCHANGER THE COMBINATION OF AN ENCLOSURE, PARTITION MEANS IN SAID ENCLOSURE, SAID ENCLOSURE DEFINING FIRST, SECOND, AND THIRD COMPARTMENTS, MEANS COMMUNICATING SAID FIRST COMPARTMENT WITH HEAT EXCHANGE MEDIUM IN A PREDETERMINED FIRST CONDITION, MEANS COMMUNICATING SAID SECOND COMPARTMENT WITH SAID HEAT EXCHANGE MEDIUM IN A PREDETERMINED SECOND CONDITION, PLURAL HEAT EXCHANGER TUBES COMMUNICATING SAID FIRST COMPARTMENT WITH SAID THIRD COMPARTMENT, SAID TUBES PASSING THROUGH SAID SECOND COMPARTMENT TO BRING HEAT EXCHANGE MEDIUM IN SAID FIRST PREDETERMINED CONDITION INTO HEAT EXCHANGE RELATIONSHIP WITH HEAT EXCHANGE MEDIUM IN SAID SECOND PREDETERMINED CONDITION, AND ELASTOMERIC SEALING 